Rotary couplings have been used in the oil and gas industry and also in other fluid handling industries for a number of years. Oil pipelines associated with exploration drilling commonly include a series of interconnected sections of steel pipe each of which include a male connecting piece at one end a female connecting piece at the other end. The inlets and outlets to be connected by such pipelines can be at various positions relative to one another. It is not always possible or practical to provide rigid pipelines particularly suited to all applications.
Consequently it is a common practice to interconnect lengths of pipe of various configurations using a rotary or swivel joint to accommodate dynamic pipe expansion relative axial rotation of adjacent lengths of pipe that can occur.
Rotary couplings often use annular sealing or packing rings axially compressed between adjacent internal radially extended faces of male and female connecting pieces.
In practice the reliability and maneuverability of rotary couplings has been an issue and therefore there is a need for a rotary coupling which is extremely reliable under severe conditions while also being easy to manipulate in the field.